aha1542: Stop using scsi_module.c

Convert aha1542 to use scsi_add_host instead of scsi_module.c
Use pnp_driver and isa_driver to manage cards.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>